1. Field of the Invention
The present invention relates to a PTT (Push-to-Talk) service, and particularly, to a method for processing a talk burst (e.g., right to speak, floor request) of a PTT service by which, when one PTT terminal requests permission to send a talk burst, while the talk burst has already been allocated to another PTT terminal, and a PTT server denies the request for the permission to send the talk burst.
2. Background of the Related Art
PTT (Push-To-Talk) refers to a half-duplex communication scheme whereby only one user is given a right to talk (i.e., floor grant, talk burst grant, etc.), as in a walkie-talkie service, and provides a one-to-one or one-to-many call conversation service. In other words, a user that has been granted the right to talk is said to have been granted the “floor” or granted a “talk burst”, and these expressions can thus be used interchangeably.
In general, a PTT service system includes a PTT terminal having a PTT key (button) used for requesting permission to send a talk burst (i.e., a floor request), and a PTT server for controlling a talk burst (e.g., right to speak, floor control, etc.) and transmission of voice and data between the PTT terminals. Namely, talk burst requests (or floor requests) from various users are granted or denied by the PTT server such that only one user (PTT terminal) at a time has the right to talk while other users must listen.
In the PTT service system having such configuration, when a user presses a key of a PTT terminal to request permission to send a talk burst, if the talk burst has not been allocated to another PTT terminal, the PTT server sends a talk burst grant (floor grant) message to the corresponding PTT terminal that requested talk burst permission. However, if the talk burst has already been allocated to another PTT terminal, the PTT server sends a talk burst deny (floor deny) message to the corresponding PTT terminal.
The talk burst deny message indicates that when a user of a PTT terminal requests permission to send a talk burst while another PTT terminal already has the talk burst, the PTT server cannot allocate the talk burst to the PTT terminal having requested the talk burst. Namely, in the related art PTT service system, the PTT server sends the talk burst deny message only to the PTT terminal that sent a talk burst request message.
In general, a call conversation can be freely made in bi-directional communications without any distinction between the speaker and the listener. However, in half-duplex communications, such as a PTT service, the speaker and the listener are clearly distinguished and only a user who has a talk burst can be the speaker.
As mentioned above, the related art PTT service is disadvantageous in that, if a particular user has a talk burst, he does not know about any information regarding the state of other PTT terminals which have no talk burst, i.e., that do not have the right to speak.